Phil’s Findings #7: Human Haptics

04 July 2011

Phil Howes, the Institute of Making’s post-doc researcher, shares his thoughts and findings as he delves into the sensoaesthetic world of materials. Check this space every Monday for Phil's latest posting.

The study of human haptics is an exciting and rapidly evolving field. It has the potential to revolutionise the way in which we interact with our everyday environment, and with each other. Furthermore, haptic devices are already making an impact on how we interact with some technologies.

The haptic system governs our sense of touch. Things like vibrating mobile phones or computer games controllers already tap into your sense of touch as a way of giving you information. However, it is anticipated that new technologies which feed sophisticated information into the human haptic system will evolve in the same way visual computer graphics have gone from rudimentary representations of real life to extremely sophisticated graphics which are sometimes indecipherable from real life. Imagine wearing a pair of gloves which relay all the sensations of heat, pressure, or even pain, which are experienced as your computer game character touches things in a virtual environment. Imagine being able to transfer manual operations over the internet through a haptic device. Imagine a surgeon being able to perform a life saving operation on someone halfway across the world through a haptic machine which performs the operation and allows direct feedback of sensation into the surgeon’s hands. Such things are already under active development.

So what is the haptic system? Well, within the human body, the role of haptic system can be broken down into two distinct tasks; working out what we are touching, and where it is. The what task is taken care of by sensors in our skin, and for that reason it is referred to as the cutaneous subsystem of the haptic system. These sensors are nerve receptors embedded in our skin which are capable of detecting pressure, vibration, heat and noxious stimulation. The sensitivity of your skin to different stimuli varies across the body, with the hands and face exhibiting high touch sensitivity, and areas such as the forearm or thigh being less sensitive. Our hands provide us with a powerful means of exploring material shapes and surfaces, and we are able to discern a huge amount of information from the sensations we experience through them by touch.

The where task involves detecting where on the body you are touched, and also where in the space around you the object that you are touching you is. Knowing where on your body you have been touched is a case of your brain working out from where on the skin the nervous signal was sent. Although it sounds simple, conditions such as phantom limbs, where amputees still feel sensations from parts of their body which they no longer have, indicate a large level of complexity in how nerve signals are deciphered in the brain. The ability to identify where in the space around you a stimulus is detected is a vital part of haptic perception. Imagine you are in complete darkness, and you are waving your arms around in front of you to help you navigate through a room. As your hands come into contact with something, you instantly understand not only the nature of the thing your touching (i.e. hard, soft, furry etc), but also where it is in relation to your body, and if you need to take avoiding action. In fact, you have a great awareness of where the various parts of your body are in space, and this is vital in enabling you to interact with the environment.

So, by tapping into your what and where systems, it will be possible for technology to feed your sense of touch in the same way it feeds your sense of vision. Information transfer between you and your computer will become ever more rapid and sophisticated, and the use of technology will move into a truly multisensory realm.